xref: /linux-6.15/include/linux/interrupt.h (revision 9d64fc08)
1 /* interrupt.h */
2 #ifndef _LINUX_INTERRUPT_H
3 #define _LINUX_INTERRUPT_H
4 
5 #include <linux/kernel.h>
6 #include <linux/linkage.h>
7 #include <linux/bitops.h>
8 #include <linux/preempt.h>
9 #include <linux/cpumask.h>
10 #include <linux/irqreturn.h>
11 #include <linux/irqnr.h>
12 #include <linux/hardirq.h>
13 #include <linux/irqflags.h>
14 #include <linux/hrtimer.h>
15 #include <linux/kref.h>
16 #include <linux/workqueue.h>
17 
18 #include <linux/atomic.h>
19 #include <asm/ptrace.h>
20 #include <asm/irq.h>
21 #include <asm/sections.h>
22 
23 /*
24  * These correspond to the IORESOURCE_IRQ_* defines in
25  * linux/ioport.h to select the interrupt line behaviour.  When
26  * requesting an interrupt without specifying a IRQF_TRIGGER, the
27  * setting should be assumed to be "as already configured", which
28  * may be as per machine or firmware initialisation.
29  */
30 #define IRQF_TRIGGER_NONE	0x00000000
31 #define IRQF_TRIGGER_RISING	0x00000001
32 #define IRQF_TRIGGER_FALLING	0x00000002
33 #define IRQF_TRIGGER_HIGH	0x00000004
34 #define IRQF_TRIGGER_LOW	0x00000008
35 #define IRQF_TRIGGER_MASK	(IRQF_TRIGGER_HIGH | IRQF_TRIGGER_LOW | \
36 				 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING)
37 #define IRQF_TRIGGER_PROBE	0x00000010
38 
39 /*
40  * These flags used only by the kernel as part of the
41  * irq handling routines.
42  *
43  * IRQF_SHARED - allow sharing the irq among several devices
44  * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur
45  * IRQF_TIMER - Flag to mark this interrupt as timer interrupt
46  * IRQF_PERCPU - Interrupt is per cpu
47  * IRQF_NOBALANCING - Flag to exclude this interrupt from irq balancing
48  * IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
49  *                registered first in an shared interrupt is considered for
50  *                performance reasons)
51  * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
52  *                Used by threaded interrupts which need to keep the
53  *                irq line disabled until the threaded handler has been run.
54  * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend.  Does not guarantee
55  *                   that this interrupt will wake the system from a suspended
56  *                   state.  See Documentation/power/suspend-and-interrupts.txt
57  * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set
58  * IRQF_NO_THREAD - Interrupt cannot be threaded
59  * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device
60  *                resume time.
61  * IRQF_COND_SUSPEND - If the IRQ is shared with a NO_SUSPEND user, execute this
62  *                interrupt handler after suspending interrupts. For system
63  *                wakeup devices users need to implement wakeup detection in
64  *                their interrupt handlers.
65  */
66 #define IRQF_SHARED		0x00000080
67 #define IRQF_PROBE_SHARED	0x00000100
68 #define __IRQF_TIMER		0x00000200
69 #define IRQF_PERCPU		0x00000400
70 #define IRQF_NOBALANCING	0x00000800
71 #define IRQF_IRQPOLL		0x00001000
72 #define IRQF_ONESHOT		0x00002000
73 #define IRQF_NO_SUSPEND		0x00004000
74 #define IRQF_FORCE_RESUME	0x00008000
75 #define IRQF_NO_THREAD		0x00010000
76 #define IRQF_EARLY_RESUME	0x00020000
77 #define IRQF_COND_SUSPEND	0x00040000
78 
79 #define IRQF_TIMER		(__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD)
80 
81 /*
82  * These values can be returned by request_any_context_irq() and
83  * describe the context the interrupt will be run in.
84  *
85  * IRQC_IS_HARDIRQ - interrupt runs in hardirq context
86  * IRQC_IS_NESTED - interrupt runs in a nested threaded context
87  */
88 enum {
89 	IRQC_IS_HARDIRQ	= 0,
90 	IRQC_IS_NESTED,
91 };
92 
93 typedef irqreturn_t (*irq_handler_t)(int, void *);
94 
95 /**
96  * struct irqaction - per interrupt action descriptor
97  * @handler:	interrupt handler function
98  * @name:	name of the device
99  * @dev_id:	cookie to identify the device
100  * @percpu_dev_id:	cookie to identify the device
101  * @next:	pointer to the next irqaction for shared interrupts
102  * @irq:	interrupt number
103  * @flags:	flags (see IRQF_* above)
104  * @thread_fn:	interrupt handler function for threaded interrupts
105  * @thread:	thread pointer for threaded interrupts
106  * @secondary:	pointer to secondary irqaction (force threading)
107  * @thread_flags:	flags related to @thread
108  * @thread_mask:	bitmask for keeping track of @thread activity
109  * @dir:	pointer to the proc/irq/NN/name entry
110  */
111 struct irqaction {
112 	irq_handler_t		handler;
113 	void			*dev_id;
114 	void __percpu		*percpu_dev_id;
115 	struct irqaction	*next;
116 	irq_handler_t		thread_fn;
117 	struct task_struct	*thread;
118 	struct irqaction	*secondary;
119 	unsigned int		irq;
120 	unsigned int		flags;
121 	unsigned long		thread_flags;
122 	unsigned long		thread_mask;
123 	const char		*name;
124 	struct proc_dir_entry	*dir;
125 } ____cacheline_internodealigned_in_smp;
126 
127 extern irqreturn_t no_action(int cpl, void *dev_id);
128 
129 /*
130  * If a (PCI) device interrupt is not connected we set dev->irq to
131  * IRQ_NOTCONNECTED. This causes request_irq() to fail with -ENOTCONN, so we
132  * can distingiush that case from other error returns.
133  *
134  * 0x80000000 is guaranteed to be outside the available range of interrupts
135  * and easy to distinguish from other possible incorrect values.
136  */
137 #define IRQ_NOTCONNECTED	(1U << 31)
138 
139 extern int __must_check
140 request_threaded_irq(unsigned int irq, irq_handler_t handler,
141 		     irq_handler_t thread_fn,
142 		     unsigned long flags, const char *name, void *dev);
143 
144 static inline int __must_check
145 request_irq(unsigned int irq, irq_handler_t handler, unsigned long flags,
146 	    const char *name, void *dev)
147 {
148 	return request_threaded_irq(irq, handler, NULL, flags, name, dev);
149 }
150 
151 extern int __must_check
152 request_any_context_irq(unsigned int irq, irq_handler_t handler,
153 			unsigned long flags, const char *name, void *dev_id);
154 
155 extern int __must_check
156 __request_percpu_irq(unsigned int irq, irq_handler_t handler,
157 		     unsigned long flags, const char *devname,
158 		     void __percpu *percpu_dev_id);
159 
160 static inline int __must_check
161 request_percpu_irq(unsigned int irq, irq_handler_t handler,
162 		   const char *devname, void __percpu *percpu_dev_id)
163 {
164 	return __request_percpu_irq(irq, handler, 0,
165 				    devname, percpu_dev_id);
166 }
167 
168 extern const void *free_irq(unsigned int, void *);
169 extern void free_percpu_irq(unsigned int, void __percpu *);
170 
171 struct device;
172 
173 extern int __must_check
174 devm_request_threaded_irq(struct device *dev, unsigned int irq,
175 			  irq_handler_t handler, irq_handler_t thread_fn,
176 			  unsigned long irqflags, const char *devname,
177 			  void *dev_id);
178 
179 static inline int __must_check
180 devm_request_irq(struct device *dev, unsigned int irq, irq_handler_t handler,
181 		 unsigned long irqflags, const char *devname, void *dev_id)
182 {
183 	return devm_request_threaded_irq(dev, irq, handler, NULL, irqflags,
184 					 devname, dev_id);
185 }
186 
187 extern int __must_check
188 devm_request_any_context_irq(struct device *dev, unsigned int irq,
189 		 irq_handler_t handler, unsigned long irqflags,
190 		 const char *devname, void *dev_id);
191 
192 extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id);
193 
194 /*
195  * On lockdep we dont want to enable hardirqs in hardirq
196  * context. Use local_irq_enable_in_hardirq() to annotate
197  * kernel code that has to do this nevertheless (pretty much
198  * the only valid case is for old/broken hardware that is
199  * insanely slow).
200  *
201  * NOTE: in theory this might break fragile code that relies
202  * on hardirq delivery - in practice we dont seem to have such
203  * places left. So the only effect should be slightly increased
204  * irqs-off latencies.
205  */
206 #ifdef CONFIG_LOCKDEP
207 # define local_irq_enable_in_hardirq()	do { } while (0)
208 #else
209 # define local_irq_enable_in_hardirq()	local_irq_enable()
210 #endif
211 
212 extern void disable_irq_nosync(unsigned int irq);
213 extern bool disable_hardirq(unsigned int irq);
214 extern void disable_irq(unsigned int irq);
215 extern void disable_percpu_irq(unsigned int irq);
216 extern void enable_irq(unsigned int irq);
217 extern void enable_percpu_irq(unsigned int irq, unsigned int type);
218 extern bool irq_percpu_is_enabled(unsigned int irq);
219 extern void irq_wake_thread(unsigned int irq, void *dev_id);
220 
221 /* The following three functions are for the core kernel use only. */
222 extern void suspend_device_irqs(void);
223 extern void resume_device_irqs(void);
224 
225 /**
226  * struct irq_affinity_notify - context for notification of IRQ affinity changes
227  * @irq:		Interrupt to which notification applies
228  * @kref:		Reference count, for internal use
229  * @work:		Work item, for internal use
230  * @notify:		Function to be called on change.  This will be
231  *			called in process context.
232  * @release:		Function to be called on release.  This will be
233  *			called in process context.  Once registered, the
234  *			structure must only be freed when this function is
235  *			called or later.
236  */
237 struct irq_affinity_notify {
238 	unsigned int irq;
239 	struct kref kref;
240 	struct work_struct work;
241 	void (*notify)(struct irq_affinity_notify *, const cpumask_t *mask);
242 	void (*release)(struct kref *ref);
243 };
244 
245 /**
246  * struct irq_affinity - Description for automatic irq affinity assignements
247  * @pre_vectors:	Don't apply affinity to @pre_vectors at beginning of
248  *			the MSI(-X) vector space
249  * @post_vectors:	Don't apply affinity to @post_vectors at end of
250  *			the MSI(-X) vector space
251  */
252 struct irq_affinity {
253 	int	pre_vectors;
254 	int	post_vectors;
255 };
256 
257 #if defined(CONFIG_SMP)
258 
259 extern cpumask_var_t irq_default_affinity;
260 
261 /* Internal implementation. Use the helpers below */
262 extern int __irq_set_affinity(unsigned int irq, const struct cpumask *cpumask,
263 			      bool force);
264 
265 /**
266  * irq_set_affinity - Set the irq affinity of a given irq
267  * @irq:	Interrupt to set affinity
268  * @cpumask:	cpumask
269  *
270  * Fails if cpumask does not contain an online CPU
271  */
272 static inline int
273 irq_set_affinity(unsigned int irq, const struct cpumask *cpumask)
274 {
275 	return __irq_set_affinity(irq, cpumask, false);
276 }
277 
278 /**
279  * irq_force_affinity - Force the irq affinity of a given irq
280  * @irq:	Interrupt to set affinity
281  * @cpumask:	cpumask
282  *
283  * Same as irq_set_affinity, but without checking the mask against
284  * online cpus.
285  *
286  * Solely for low level cpu hotplug code, where we need to make per
287  * cpu interrupts affine before the cpu becomes online.
288  */
289 static inline int
290 irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
291 {
292 	return __irq_set_affinity(irq, cpumask, true);
293 }
294 
295 extern int irq_can_set_affinity(unsigned int irq);
296 extern int irq_select_affinity(unsigned int irq);
297 
298 extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
299 
300 extern int
301 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify);
302 
303 struct cpumask *irq_create_affinity_masks(int nvec, const struct irq_affinity *affd);
304 int irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd);
305 
306 #else /* CONFIG_SMP */
307 
308 static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m)
309 {
310 	return -EINVAL;
311 }
312 
313 static inline int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
314 {
315 	return 0;
316 }
317 
318 static inline int irq_can_set_affinity(unsigned int irq)
319 {
320 	return 0;
321 }
322 
323 static inline int irq_select_affinity(unsigned int irq)  { return 0; }
324 
325 static inline int irq_set_affinity_hint(unsigned int irq,
326 					const struct cpumask *m)
327 {
328 	return -EINVAL;
329 }
330 
331 static inline int
332 irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify)
333 {
334 	return 0;
335 }
336 
337 static inline struct cpumask *
338 irq_create_affinity_masks(int nvec, const struct irq_affinity *affd)
339 {
340 	return NULL;
341 }
342 
343 static inline int
344 irq_calc_affinity_vectors(int minvec, int maxvec, const struct irq_affinity *affd)
345 {
346 	return maxvec;
347 }
348 
349 #endif /* CONFIG_SMP */
350 
351 /*
352  * Special lockdep variants of irq disabling/enabling.
353  * These should be used for locking constructs that
354  * know that a particular irq context which is disabled,
355  * and which is the only irq-context user of a lock,
356  * that it's safe to take the lock in the irq-disabled
357  * section without disabling hardirqs.
358  *
359  * On !CONFIG_LOCKDEP they are equivalent to the normal
360  * irq disable/enable methods.
361  */
362 static inline void disable_irq_nosync_lockdep(unsigned int irq)
363 {
364 	disable_irq_nosync(irq);
365 #ifdef CONFIG_LOCKDEP
366 	local_irq_disable();
367 #endif
368 }
369 
370 static inline void disable_irq_nosync_lockdep_irqsave(unsigned int irq, unsigned long *flags)
371 {
372 	disable_irq_nosync(irq);
373 #ifdef CONFIG_LOCKDEP
374 	local_irq_save(*flags);
375 #endif
376 }
377 
378 static inline void disable_irq_lockdep(unsigned int irq)
379 {
380 	disable_irq(irq);
381 #ifdef CONFIG_LOCKDEP
382 	local_irq_disable();
383 #endif
384 }
385 
386 static inline void enable_irq_lockdep(unsigned int irq)
387 {
388 #ifdef CONFIG_LOCKDEP
389 	local_irq_enable();
390 #endif
391 	enable_irq(irq);
392 }
393 
394 static inline void enable_irq_lockdep_irqrestore(unsigned int irq, unsigned long *flags)
395 {
396 #ifdef CONFIG_LOCKDEP
397 	local_irq_restore(*flags);
398 #endif
399 	enable_irq(irq);
400 }
401 
402 /* IRQ wakeup (PM) control: */
403 extern int irq_set_irq_wake(unsigned int irq, unsigned int on);
404 
405 static inline int enable_irq_wake(unsigned int irq)
406 {
407 	return irq_set_irq_wake(irq, 1);
408 }
409 
410 static inline int disable_irq_wake(unsigned int irq)
411 {
412 	return irq_set_irq_wake(irq, 0);
413 }
414 
415 /*
416  * irq_get_irqchip_state/irq_set_irqchip_state specific flags
417  */
418 enum irqchip_irq_state {
419 	IRQCHIP_STATE_PENDING,		/* Is interrupt pending? */
420 	IRQCHIP_STATE_ACTIVE,		/* Is interrupt in progress? */
421 	IRQCHIP_STATE_MASKED,		/* Is interrupt masked? */
422 	IRQCHIP_STATE_LINE_LEVEL,	/* Is IRQ line high? */
423 };
424 
425 extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
426 				 bool *state);
427 extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which,
428 				 bool state);
429 
430 #ifdef CONFIG_IRQ_FORCED_THREADING
431 extern bool force_irqthreads;
432 #else
433 #define force_irqthreads	(0)
434 #endif
435 
436 #ifndef __ARCH_SET_SOFTIRQ_PENDING
437 #define set_softirq_pending(x) (local_softirq_pending() = (x))
438 #define or_softirq_pending(x)  (local_softirq_pending() |= (x))
439 #endif
440 
441 /* Some architectures might implement lazy enabling/disabling of
442  * interrupts. In some cases, such as stop_machine, we might want
443  * to ensure that after a local_irq_disable(), interrupts have
444  * really been disabled in hardware. Such architectures need to
445  * implement the following hook.
446  */
447 #ifndef hard_irq_disable
448 #define hard_irq_disable()	do { } while(0)
449 #endif
450 
451 /* PLEASE, avoid to allocate new softirqs, if you need not _really_ high
452    frequency threaded job scheduling. For almost all the purposes
453    tasklets are more than enough. F.e. all serial device BHs et
454    al. should be converted to tasklets, not to softirqs.
455  */
456 
457 enum
458 {
459 	HI_SOFTIRQ=0,
460 	TIMER_SOFTIRQ,
461 	NET_TX_SOFTIRQ,
462 	NET_RX_SOFTIRQ,
463 	BLOCK_SOFTIRQ,
464 	IRQ_POLL_SOFTIRQ,
465 	TASKLET_SOFTIRQ,
466 	SCHED_SOFTIRQ,
467 	HRTIMER_SOFTIRQ, /* Unused, but kept as tools rely on the
468 			    numbering. Sigh! */
469 	RCU_SOFTIRQ,    /* Preferable RCU should always be the last softirq */
470 
471 	NR_SOFTIRQS
472 };
473 
474 #define SOFTIRQ_STOP_IDLE_MASK (~(1 << RCU_SOFTIRQ))
475 
476 /* map softirq index to softirq name. update 'softirq_to_name' in
477  * kernel/softirq.c when adding a new softirq.
478  */
479 extern const char * const softirq_to_name[NR_SOFTIRQS];
480 
481 /* softirq mask and active fields moved to irq_cpustat_t in
482  * asm/hardirq.h to get better cache usage.  KAO
483  */
484 
485 struct softirq_action
486 {
487 	void	(*action)(struct softirq_action *);
488 };
489 
490 asmlinkage void do_softirq(void);
491 asmlinkage void __do_softirq(void);
492 
493 #ifdef __ARCH_HAS_DO_SOFTIRQ
494 void do_softirq_own_stack(void);
495 #else
496 static inline void do_softirq_own_stack(void)
497 {
498 	__do_softirq();
499 }
500 #endif
501 
502 extern void open_softirq(int nr, void (*action)(struct softirq_action *));
503 extern void softirq_init(void);
504 extern void __raise_softirq_irqoff(unsigned int nr);
505 
506 extern void raise_softirq_irqoff(unsigned int nr);
507 extern void raise_softirq(unsigned int nr);
508 
509 DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
510 
511 static inline struct task_struct *this_cpu_ksoftirqd(void)
512 {
513 	return this_cpu_read(ksoftirqd);
514 }
515 
516 /* Tasklets --- multithreaded analogue of BHs.
517 
518    Main feature differing them of generic softirqs: tasklet
519    is running only on one CPU simultaneously.
520 
521    Main feature differing them of BHs: different tasklets
522    may be run simultaneously on different CPUs.
523 
524    Properties:
525    * If tasklet_schedule() is called, then tasklet is guaranteed
526      to be executed on some cpu at least once after this.
527    * If the tasklet is already scheduled, but its execution is still not
528      started, it will be executed only once.
529    * If this tasklet is already running on another CPU (or schedule is called
530      from tasklet itself), it is rescheduled for later.
531    * Tasklet is strictly serialized wrt itself, but not
532      wrt another tasklets. If client needs some intertask synchronization,
533      he makes it with spinlocks.
534  */
535 
536 struct tasklet_struct
537 {
538 	struct tasklet_struct *next;
539 	unsigned long state;
540 	atomic_t count;
541 	void (*func)(unsigned long);
542 	unsigned long data;
543 };
544 
545 #define DECLARE_TASKLET(name, func, data) \
546 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(0), func, data }
547 
548 #define DECLARE_TASKLET_DISABLED(name, func, data) \
549 struct tasklet_struct name = { NULL, 0, ATOMIC_INIT(1), func, data }
550 
551 
552 enum
553 {
554 	TASKLET_STATE_SCHED,	/* Tasklet is scheduled for execution */
555 	TASKLET_STATE_RUN	/* Tasklet is running (SMP only) */
556 };
557 
558 #ifdef CONFIG_SMP
559 static inline int tasklet_trylock(struct tasklet_struct *t)
560 {
561 	return !test_and_set_bit(TASKLET_STATE_RUN, &(t)->state);
562 }
563 
564 static inline void tasklet_unlock(struct tasklet_struct *t)
565 {
566 	smp_mb__before_atomic();
567 	clear_bit(TASKLET_STATE_RUN, &(t)->state);
568 }
569 
570 static inline void tasklet_unlock_wait(struct tasklet_struct *t)
571 {
572 	while (test_bit(TASKLET_STATE_RUN, &(t)->state)) { barrier(); }
573 }
574 #else
575 #define tasklet_trylock(t) 1
576 #define tasklet_unlock_wait(t) do { } while (0)
577 #define tasklet_unlock(t) do { } while (0)
578 #endif
579 
580 extern void __tasklet_schedule(struct tasklet_struct *t);
581 
582 static inline void tasklet_schedule(struct tasklet_struct *t)
583 {
584 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
585 		__tasklet_schedule(t);
586 }
587 
588 extern void __tasklet_hi_schedule(struct tasklet_struct *t);
589 
590 static inline void tasklet_hi_schedule(struct tasklet_struct *t)
591 {
592 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
593 		__tasklet_hi_schedule(t);
594 }
595 
596 extern void __tasklet_hi_schedule_first(struct tasklet_struct *t);
597 
598 /*
599  * This version avoids touching any other tasklets. Needed for kmemcheck
600  * in order not to take any page faults while enqueueing this tasklet;
601  * consider VERY carefully whether you really need this or
602  * tasklet_hi_schedule()...
603  */
604 static inline void tasklet_hi_schedule_first(struct tasklet_struct *t)
605 {
606 	if (!test_and_set_bit(TASKLET_STATE_SCHED, &t->state))
607 		__tasklet_hi_schedule_first(t);
608 }
609 
610 
611 static inline void tasklet_disable_nosync(struct tasklet_struct *t)
612 {
613 	atomic_inc(&t->count);
614 	smp_mb__after_atomic();
615 }
616 
617 static inline void tasklet_disable(struct tasklet_struct *t)
618 {
619 	tasklet_disable_nosync(t);
620 	tasklet_unlock_wait(t);
621 	smp_mb();
622 }
623 
624 static inline void tasklet_enable(struct tasklet_struct *t)
625 {
626 	smp_mb__before_atomic();
627 	atomic_dec(&t->count);
628 }
629 
630 extern void tasklet_kill(struct tasklet_struct *t);
631 extern void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu);
632 extern void tasklet_init(struct tasklet_struct *t,
633 			 void (*func)(unsigned long), unsigned long data);
634 
635 struct tasklet_hrtimer {
636 	struct hrtimer		timer;
637 	struct tasklet_struct	tasklet;
638 	enum hrtimer_restart	(*function)(struct hrtimer *);
639 };
640 
641 extern void
642 tasklet_hrtimer_init(struct tasklet_hrtimer *ttimer,
643 		     enum hrtimer_restart (*function)(struct hrtimer *),
644 		     clockid_t which_clock, enum hrtimer_mode mode);
645 
646 static inline
647 void tasklet_hrtimer_start(struct tasklet_hrtimer *ttimer, ktime_t time,
648 			   const enum hrtimer_mode mode)
649 {
650 	hrtimer_start(&ttimer->timer, time, mode);
651 }
652 
653 static inline
654 void tasklet_hrtimer_cancel(struct tasklet_hrtimer *ttimer)
655 {
656 	hrtimer_cancel(&ttimer->timer);
657 	tasklet_kill(&ttimer->tasklet);
658 }
659 
660 /*
661  * Autoprobing for irqs:
662  *
663  * probe_irq_on() and probe_irq_off() provide robust primitives
664  * for accurate IRQ probing during kernel initialization.  They are
665  * reasonably simple to use, are not "fooled" by spurious interrupts,
666  * and, unlike other attempts at IRQ probing, they do not get hung on
667  * stuck interrupts (such as unused PS2 mouse interfaces on ASUS boards).
668  *
669  * For reasonably foolproof probing, use them as follows:
670  *
671  * 1. clear and/or mask the device's internal interrupt.
672  * 2. sti();
673  * 3. irqs = probe_irq_on();      // "take over" all unassigned idle IRQs
674  * 4. enable the device and cause it to trigger an interrupt.
675  * 5. wait for the device to interrupt, using non-intrusive polling or a delay.
676  * 6. irq = probe_irq_off(irqs);  // get IRQ number, 0=none, negative=multiple
677  * 7. service the device to clear its pending interrupt.
678  * 8. loop again if paranoia is required.
679  *
680  * probe_irq_on() returns a mask of allocated irq's.
681  *
682  * probe_irq_off() takes the mask as a parameter,
683  * and returns the irq number which occurred,
684  * or zero if none occurred, or a negative irq number
685  * if more than one irq occurred.
686  */
687 
688 #if !defined(CONFIG_GENERIC_IRQ_PROBE)
689 static inline unsigned long probe_irq_on(void)
690 {
691 	return 0;
692 }
693 static inline int probe_irq_off(unsigned long val)
694 {
695 	return 0;
696 }
697 static inline unsigned int probe_irq_mask(unsigned long val)
698 {
699 	return 0;
700 }
701 #else
702 extern unsigned long probe_irq_on(void);	/* returns 0 on failure */
703 extern int probe_irq_off(unsigned long);	/* returns 0 or negative on failure */
704 extern unsigned int probe_irq_mask(unsigned long);	/* returns mask of ISA interrupts */
705 #endif
706 
707 #ifdef CONFIG_PROC_FS
708 /* Initialize /proc/irq/ */
709 extern void init_irq_proc(void);
710 #else
711 static inline void init_irq_proc(void)
712 {
713 }
714 #endif
715 
716 #ifdef CONFIG_IRQ_TIMINGS
717 void irq_timings_enable(void);
718 void irq_timings_disable(void);
719 u64 irq_timings_next_event(u64 now);
720 #endif
721 
722 struct seq_file;
723 int show_interrupts(struct seq_file *p, void *v);
724 int arch_show_interrupts(struct seq_file *p, int prec);
725 
726 extern int early_irq_init(void);
727 extern int arch_probe_nr_irqs(void);
728 extern int arch_early_irq_init(void);
729 
730 /*
731  * We want to know which function is an entrypoint of a hardirq or a softirq.
732  */
733 #define __irq_entry		 __attribute__((__section__(".irqentry.text")))
734 #define __softirq_entry  \
735 	__attribute__((__section__(".softirqentry.text")))
736 
737 #endif
738